Kamagra Australia means a drug product known as Kamagra Oral Jelly 100mg with sildenafil citrate as its active pharmaceutical substance. Sildenafil is a phosphodiesterase type-5 (PDE5) inhibitor intended for erectile dysfunction treatment. The 100 mg means the content of sildenafil in the preparation, whereas the oral jelly indicates the drug dosage form for Kamagra Australia. Sildenafil functions due to the physiological mechanism of penile erection. In the presence of sexual stimulation, nitric oxide increases the concentration of cGMP in penile tissue. Sildenafil is a PDE5 inhibitor that blocks the breakdown of cGMP. Sustained cGMP leads to the relaxation of smooth muscles and increased blood flow into the penis contributing to penile erection under the conditions of sexual stimulation. Erectile dysfunction treatment requires sexual stimulation only, so the use of sildenafil is unable to produce an erection independently of the sexual stimulation. The main pharmacological features of the drug are sildenafil citrate, 100 mg, PDE5 inhibition, oral jelly preparation, and erectile dysfunction treatment. Besides that, sildenafil products have a contraindication with nitrate drugs that can lead to hypotension.